The present invention relates generally to burial vaults. More particularly the present invention is directed to a two piece polystyrene burial vault adapted to compressively surround and seal an internally disposed casket during and after the burial process. The invention is believed best classified in United States Class 52, subclass 138.
The known prior art reveals a plurality of burial vaults comprising one or more cooperative parts which are adapted to be fitted together. Burial vaults exist of the "air seal" type are adapted to provide a seal for enclosing the interiorly disposed casket. Air seal type burial vaults comprised of molded synthetic plastic "resinous" materials are also well known in the art. However, their sealing ability is in question and their strength has been shown to be inadequate.
U.S. Pat. No. 235,376, issued to Orr on Dec. 14, 1880 discloses a multi-piece coffin in which a top section is adapted to be placed on a lower containment section and in which the lower section includes offset shoulders for receiving the straps of the conventional burial lowering device. Work Patent 4,253,220, issued on Mar. 3, 1981, discloses a burial vault in which a lower container is adapted to receive a coffin to be disposed therewithin, and an upper top is fitted to the lower container. However, compression of the top against the lower base does not provide an air tight or water tight seal which simultaneously pressurizes the interior of the vault after burying, and which inherently resists the corrosive effects of water and the like.
A mausoleum device is shown in U.S. Pat. No. 1,466,725, issued Sept. 4, 1923 to McMeans. This invention discloses a lower base having a plurality of spaced apart tapered extensions rising upwardly from the floor of the base for supporting in elevated disposition an internally disposed casket. An upper cover is placed over the casket and the base but no operationally effective seal is provided by the action of the cover upon the base.
Perhaps the most pertinent prior art known to applicant is disclosed in United States Patents U.S. Pat. Nos. 3,208,186 and 3,208,188 issued to B. A. Fulton on Sept. 28, 1965. Of these patents, U.S. Pat. No. 3,208,188 is most germane. It discloses a lower base adapted to be lowered into the ground, and which receives an upper, box-like cover adapted to be fitted to the outer peripheral edges of the base member. A plurality of internally disposed reinforcing ribs are associated with the interior surface of the cover.
However, to my knowledge there has never been either a burial vault or casket comprised of polystyrene because it has hitherto been believed that such material is not strong enough for the intended purpose. Moreover, it is not believed to be known in the art to provide a two piece burial vault of the air seal type in which subsequent pressure provided by the accumulated dirt disposed within the grave urges the two members together in such a fashion so as to continuously maintain an internal seal.
In particular, it would seem advantageous to provide a resilient two piece air seal burial vault system in which the interior, in which the casket is disposed, becomes pressurized by slight deformation of the top in compression thereof against the bottom. It would also seem desirable to provide an overall configuration in which the geometry of the various parts aids in strengthening the overall combination to enable the successful use of polystyrene molded components.